SorptionsDesorptionsExperimente

SorptionsDesorptionsExperimente are experimental procedures used to study adsorption and desorption phenomena of molecules on solid surfaces or within porous materials. They are fundamental for characterizing surface properties, interaction strengths, and pore structures, with broad applications in catalysis, environmental engineering, and material science.

In typical gas-based sorption experiments, a sample is degassed to remove contaminants, then exposed to a sorbate (often nitrogen or argon) at controlled temperatures. The amount adsorbed is measured as a function of relative pressure (P/P0), yielding an adsorption-desorption isotherm. From these data, surface area can be estimated using the Brunauer–Emmett–Teller (BET) method, while pore size distribution and volume are inferred with analyses such as BJH, t-plot, or other model fits. The isotherm shape and any hysteresis between the adsorption and desorption branches provide information about pore geometry and connectivity.

Common materials studied include activated carbons, silica, zeolites, metal-organic frameworks (MOFs), porous polymers, and clays. Beyond gas sorption, liquid-phase sorption experiments explore reversible binding of solutes to surfaces, informing sorption coefficients and isotherm models like Langmuir, Freundlich, or Sips, which describe interaction strength and capacity.

Extensions of SorptionsDesorptionsExperimente include temperature-programmed desorption (TPD), temperature-programmed adsorption, and coupling with gravimetric or calorimetric measurements, enabling kinetic and thermodynamic analyses. Limitations arise from sample history, degassing effectiveness, and pore hysteresis, which can complicate interpretation.

Overall, these experiments provide essential quantitative insights into surface area, porosity, and adsorption mechanisms, supporting the design of effective adsorbents, catalysts, and materials for gas storage and environmental applications.